GB621819A - Improvements in and relating to inter-changeable letter signs - Google Patents

Abstract

621,819. Signs. YATES, H. R. Nov. 4, 1946. No. 32642. Convention date, April 25. [Class 3(ii)] A sign comprises a carrier interchangeably mounting a row of units detachably connected both mechanically and electrically, each of the two end units of the row, having a projecting jack received in a socket in the carrier, the secondary of a transformer being connected across the sockets and the primary of the transformer having a switch spring-biased to its "off" position and moved to "on" position by the row of units as the jacks enter the sockets. As shown in Fig. 1, a base 10 supports pairs of pillars 11 which have channels 12 for removable trays 13, each of which carries a row of interchangeable sign units 14. The units 14, Fig. 6, each comprise a rectangular casing 15 made of insulating material, and are either hollow or filled with a hardening plastic. When they are hollow a back cover is provided. Mounted on the front is a discharge tube bent to the shape of the required symbol, one end being connected to a plug 23 on a side 25 and the other to a socket 22 on the opposite side 24. The plug of one unit is arranged to engage the socket of an adjacent unit and an insulating sleeve 56 is used to protect the joint against the weather. A resistor 27 may be connected in series with the tube so that each sign element has the same resistance. The units are slidably mounted in the tray 13 which is of channel-section and has flanges 28, Fig. 3, to retain the units in the channel. Dummy units having no discharge tube but with the plug and socket connected by a resistor are used to fill any spaces. At each end of the tray 13, end-connecting units 30 are used. One of these has a plug 33 for engaging the socket 22 of the adjacent unit and the other has a socket 32 for engaging the plug 23 of the unit at that end. The members 32, 33, are connected to plugs 36 which protrude from the base of the tray 13 and which engage insulated sockets 38 mounted within the channels 12 on the base 10. The plugs 38 are connected to the high voltage secondary of a transformer 42, so that the units 14 are series connected. The primary 42 of the transformer is connected to the supply mains through a switch 45 which is actuated by the tray 13 when in position in the channels 12. The plugs 36 are of such length that they make contact with the sockets 38 before the switch is actuated. An insulating sleeve covers the portion of each plug 36 which still projects when the switch is actuated. In a modification, the trays 13 may have plugs 36 which protrude from the back instead of the base. With this construction several trays are mounted one above the other in a casing to form a hanging sign, the trays being replaceable from the front and plugging into contact strips at the rear. The trays are kept in position by a screw-on frame. In either construction the trays 13 may be omitted in which case the plug and socket connections are relied upon for rigidity.